Wall-to-wall carpeting is usually installed with an underlay or padding to provide comfortable walking. It is somewhat difficult to install such carpeting over a normal underlay because of the need to stretch the carpeting toward the wall over an underlay that tends to cling to the carpeting. This causes uneveness in the underlay and the carpeting. Contrary to other carpet and underlay structures, in this instance it would be desirable for the face of the underlay which contacts the carpeting to be of low friction so the carpet can slide easily over the underlay during installation. Relative sliding after installation is not a problem since both the carpeting and the underlay are fixed around the entire perimeter.
The underlays described in my U.S. Pat. Nos. 4,504,537 and 4,504,538 have specific properties for specialized uses, e.g., the former relates to nonslip properties as between the underlay and the wood or tile floors underneath; and the latter is designed to lay on carpeting and to support a decorative rug above it. The underlays in my two U.S. Pat. Nos. 4,668,559 and 4,725,476 have upper surfaces of low friction characteristics so as to permit wall-to-wall carpeting to slide over the underlay and not bunch or wrinkle. In more recent developments it has become popular to attach the carpeting and the underlay to each other by a suitable adhesive to eliminate any wrinkling or bunching; and also to attach the underlay to wooden or tile flooring by a suitable adhesive. These requirements demand a new set of properties for the underlay which are supplied by this invention.
It is an object of this invention to provide a process for making a carpet underlay suitable for being adhesively attached to the flooring underneath and the carpeting above. It is another object of this invention to provide a suitably tough, resilient underlay that is a comfortable base for those walking on the carpet. Still other objects will become apparent from the more detailed description which follows.